Dogs' fondness for humans has genetic basis, new study says

Unique genetic insertions, called transposons, on the Williams-Beuren syndrome critical regions (WBSCR) were strongly associated with social traits, such as seeking out humans for physical contact.

A new study pinpoints genetic variations in dogs that distinguish them from wolves and account for their natural sociability with humans.

An interdisciplinary team that included researchers from Princeton University sequenced a region of chromosome 6 in dogs, according to a university statement. They discovered many sections of canine DNA associated with social behavior.

Unique genetic insertions, called transposons, on the Williams-Beuren syndrome critical regions (WBSCR) were strongly associated with social traits, such as seeking out humans for physical contact.

Interestingly, the congenital human disorder, Williams-Beuren syndrome, which causes hyper-social behavior such as extreme talkativeness, is caused by the deletion, rather than the insertion, of genes from the genome.

"It was the remarkable similarity between the behavioral presentation of Williams-Beuren syndrome and the friendliness of domesticated dogs that suggested to us that there may be similarities in the genetic architecture of the two phenotypes," said lead co-author Bridgett vonHolt, an assistant professor in ecology and evolutionary biology at Princeton.

The team analyzed behavioral and genetic data from 18 domesticated dogs and 10 captive gray wolves that were socialized to interact with humans.

By a series experiments to test the canines' sociability traits, the researchers found that the domestic dogs showed a greater tendency to seek out humans and engage in human-oriented behavior. They also found that only dogs had transposons on the WBSCR.

"We haven't found a 'social gene,' but rather an important component that shapes animal personality and assisted the process of domesticating a wild wolf into a tame dog," vanHolt said.